# RuVector Graph - Distributed Hypergraph Database Architecture
## Executive Summary
RuVector Graph is a distributed, Neo4j-compatible hypergraph database designed for extreme performance through SIMD optimization, lock-free data structures, and intelligent query execution. It extends traditional property graph models with hyperedge support for n-ary relationships while seamlessly integrating with RuVector's vector database capabilities for hybrid semantic-graph queries.
**Key Performance Targets:**
- **10-100x faster** than Neo4j for graph traversals (SIMD + cache-optimized layouts)
- **5-50x faster** for complex pattern matching (parallel execution + JIT compilation)
- **Sub-millisecond latency** for 3-hop neighborhood queries on billion-edge graphs
- **Linear scalability** to 100+ node clusters with federation support
---
## 1. System Architecture Overview
### 1.1 High-Level Architecture
```
┌─────────────────────────────────────────────────────────────────┐
│ Client Applications │
│ (Cypher Queries, Vector+Graph Hybrid Queries) │
└──────────────────────┬──────────────────────────────────────────┘
│
▼
┌─────────────────────────────────────────────────────────────────┐
│ Query Coordinator Layer │
│ ┌──────────────┐ ┌───────────────┐ ┌────────────────────┐ │
│ │ Query Parser │─▶│ Query Planner │─▶│ Execution Engine │ │
│ │ (Cypher) │ │ (Optimizer) │ │ (SIMD+Parallel) │ │
│ └──────────────┘ └───────────────┘ └────────────────────┘ │
└──────────────────────┬──────────────────────────────────────────┘
│
▼
┌─────────────────────────────────────────────────────────────────┐
│ Federation Layer │
│ ┌────────────────┐ ┌──────────────┐ ┌──────────────────┐ │
│ │ Cluster Router │ │ Query Merger │ │ Cross-Cluster │ │
│ │ │ │ │ │ Transaction Mgr │ │
│ └────────────────┘ └──────────────┘ └──────────────────┘ │
└──────────────────────┬──────────────────────────────────────────┘
│
┌──────────────┼──────────────┐
▼ ▼ ▼
┌──────────────┐ ┌──────────────┐ ┌──────────────┐
│ Cluster 1 │ │ Cluster 2 │ │ Cluster N │
│ │ │ │ │ │
│ ┌────────┐ │ │ ┌────────┐ │ │ ┌────────┐ │
│ │ RAFT │ │ │ │ RAFT │ │ │ │ RAFT │ │
│ │ Leader │ │ │ │ Leader │ │ │ │ Leader │ │
│ └────┬───┘ │ │ └────┬───┘ │ │ └────┬───┘ │
│ │ │ │ │ │ │ │ │
│ ┌────▼────┐ │ │ ┌────▼────┐ │ │ ┌────▼────┐ │
│ │ Storage │ │ │ │ Storage │ │ │ │ Storage │ │
│ │ Engine │ │ │ │ Engine │ │ │ │ Engine │ │
│ └─────────┘ │ │ └─────────┘ │ │ └─────────┘ │
└──────────────┘ └──────────────┘ └──────────────┘
```
### 1.2 Core Design Principles
1. **SIMD-First Design**: All critical paths use SIMD intrinsics for 4-8x speedup
2. **Lock-Free Architecture**: Minimize contention with lock-free data structures
3. **Cache-Optimized Layouts**: Columnar storage and CSR graphs for cache efficiency
4. **Zero-Copy Operations**: Memory-mapped storage with direct SIMD access
5. **Adaptive Indexing**: Automatic index selection based on query patterns
6. **Hybrid Execution**: Seamlessly combine vector similarity and graph traversal
---
## 2. Data Model
### 2.1 Core Entities
```rust
/// Node: Vertex in the graph with properties and optional embedding
pub struct Node {
id: NodeId, // 64-bit ID (8 bytes)
labels: SmallVec<[LabelId; 4]>, // Inline for ≤4 labels
properties: PropertyMap, // Key-value properties
embedding: Option<Vec<f32>>, // Optional vector embedding
degree_out: u32, // Outgoing edge count
degree_in: u32, // Incoming edge count
edge_offset: u64, // Offset in edge array
}
/// Edge: Directed binary relationship
pub struct Edge {
id: EdgeId, // 64-bit ID
src: NodeId, // Source node
dst: NodeId, // Destination node
label: LabelId, // Edge type
properties: PropertyMap,
embedding: Option<Vec<f32>>, // Optional edge embedding
}
/// Hyperedge: N-ary relationship connecting multiple nodes
pub struct Hyperedge {
id: HyperedgeId, // 64-bit ID
nodes: Vec<NodeId>, // Connected nodes (ordered)
label: LabelId, // Hyperedge type
description: String, // Natural language description
properties: PropertyMap,
embedding: Vec<f32>, // Always embedded for semantic search
confidence: f32, // Relationship confidence [0,1]
}
/// Property: Strongly-typed property value
#[derive(Clone)]
pub enum PropertyValue {
Null,
Bool(bool),
Int64(i64),
Float64(f64),
String(String),
DateTime(i64), // Unix timestamp
List(Vec<PropertyValue>),
Map(HashMap<String, PropertyValue>),
}
```
### 2.2 Storage Layout
**Compressed Sparse Row (CSR) Format for Edges:**
```
Nodes: [N0, N1, N2, N3, ...]
Offsets: [0, 3, 5, 8, ...] # Edge start indices
Edges: [E0, E1, E2, E3, E4, E5, E6, E7, ...]
└─N0 edges─┘ └N1─┘ └──N2 edges──┘
```
**Benefits:**
- Cache-friendly sequential access
- SIMD-friendly: process multiple edges in parallel
- Low memory overhead: 8-16 bytes per edge
- Fast neighborhood queries: O(degree) with prefetching
### 2.3 Indexing Strategy
1. **Primary Indexes:**
- Node ID → Node (B+ Tree or HashMap)
- Edge ID → Edge (B+ Tree or HashMap)
- Hyperedge ID → Hyperedge (B+ Tree or HashMap)
2. **Secondary Indexes:**
- Label Index: LabelId → [NodeId] (Bitmap or RoaringBitmap)
- Property Index: (Key, Value) → [NodeId] (B+ Tree)
- Temporal Index: TimeRange → [HyperedgeId] (Interval Tree)
- Vector Index: Embedding → [NodeId/EdgeId] (HNSW from ruvector-core)
3. **Specialized Indexes:**
- Bipartite Index: Node ↔ Hyperedge (for hypergraph queries)
- Geospatial Index: (Lat, Lon) → [NodeId] (R-Tree)
- Full-Text Index: Text → [NodeId] (Inverted Index)
---
## 3. Module Structure
### 3.1 Crate Organization
```
ruvector-graph/
├── src/
│ ├── lib.rs # Public API and re-exports
│ │
│ ├── model/ # Data model
│ │ ├── mod.rs
│ │ ├── node.rs # Node definition
│ │ ├── edge.rs # Edge definition
│ │ ├── hyperedge.rs # Hyperedge definition
│ │ ├── property.rs # Property types and maps
│ │ └── schema.rs # Schema definitions and validation
│ │
│ ├── storage/ # Storage layer
│ │ ├── mod.rs
│ │ ├── engine.rs # Storage engine trait and orchestration
│ │ ├── csr.rs # CSR graph storage
│ │ ├── columnar.rs # Columnar property storage
│ │ ├── mmap.rs # Memory-mapped file handling
│ │ ├── wal.rs # Write-Ahead Log
│ │ └── snapshot.rs # Snapshotting and recovery
│ │
│ ├── index/ # Indexing layer
│ │ ├── mod.rs
│ │ ├── primary.rs # Primary ID indexes
│ │ ├── label.rs # Label indexes (bitmap)
│ │ ├── property.rs # Property indexes (B+ tree)
│ │ ├── temporal.rs # Temporal hyperedge indexes
│ │ ├── vector.rs # Vector similarity indexes (HNSW)
│ │ ├── bipartite.rs # Hypergraph bipartite indexes
│ │ └── adaptive.rs # Adaptive index selection
│ │
│ ├── query/ # Query processing
│ │ ├── mod.rs
│ │ ├── parser/ # Cypher parser
│ │ │ ├── mod.rs
│ │ │ ├── lexer.rs # Tokenization
│ │ │ ├── ast.rs # Abstract syntax tree
│ │ │ ├── cypher.rs # Cypher grammar
│ │ │ └── extensions.rs # RuVector extensions (vector ops)
│ │ │
│ │ ├── planner/ # Query planning and optimization
│ │ │ ├── mod.rs
│ │ │ ├── logical.rs # Logical plan generation
│ │ │ ├── physical.rs # Physical plan generation
│ │ │ ├── optimizer.rs # Rule-based optimization
│ │ │ ├── cost_model.rs # Cost-based optimization
│ │ │ └── statistics.rs # Query statistics collector
│ │ │
│ │ └── executor/ # Query execution
│ │ ├── mod.rs
│ │ ├── engine.rs # Execution engine
│ │ ├── operators.rs # Physical operators (Scan, Join, etc.)
│ │ ├── simd_ops.rs # SIMD-optimized operations
│ │ ├── parallel.rs # Parallel execution (Rayon)
│ │ ├── vectorized.rs # Vectorized execution (batch processing)
│ │ └── jit.rs # JIT compilation for hot paths (optional)
│ │
│ ├── distributed/ # Distribution layer
│ │ ├── mod.rs
│ │ ├── consensus/ # Consensus protocol
│ │ │ ├── mod.rs
│ │ │ ├── raft_ext.rs # Extended RAFT from ruvector-raft
│ │ │ ├── log.rs # Distributed transaction log
│ │ │ └── snapshot.rs # Distributed snapshots
│ │ │
│ │ ├── partitioning/ # Graph partitioning
│ │ │ ├── mod.rs
│ │ │ ├── hash.rs # Hash partitioning
│ │ │ ├── range.rs # Range partitioning
│ │ │ ├── metis.rs # METIS-based graph partitioning
│ │ │ └── adaptive.rs # Adaptive repartitioning
│ │ │
│ │ ├── replication/ # Replication
│ │ │ ├── mod.rs
│ │ │ ├── sync.rs # Synchronous replication
│ │ │ ├── async.rs # Asynchronous replication
│ │ │ └── consistency.rs # Consistency guarantees
│ │ │
│ │ └── coordination/ # Cluster coordination
│ │ ├── mod.rs
│ │ ├── cluster.rs # Cluster membership
│ │ ├── leader.rs # Leader election
│ │ └── heartbeat.rs # Health monitoring
│ │
│ ├── federation/ # Cross-cluster federation
│ │ ├── mod.rs
│ │ ├── router.rs # Query routing across clusters
│ │ ├── merger.rs # Result merging
│ │ ├── catalog.rs # Global metadata catalog
│ │ ├── transaction.rs # Cross-cluster transactions (2PC)
│ │ └── cache.rs # Federation result cache
│ │
│ ├── hybrid/ # Vector-Graph hybrid queries
│ │ ├── mod.rs
│ │ ├── vector_graph.rs # Combined vector+graph operations
│ │ ├── semantic_search.rs # Semantic graph search
│ │ ├── knn_traversal.rs # KNN + graph traversal
│ │ └── rag_hypergraph.rs # RAG with hypergraph (NeurIPS 2025)
│ │
│ ├── transaction/ # Transaction management
│ │ ├── mod.rs
│ │ ├── mvcc.rs # Multi-Version Concurrency Control
│ │ ├── isolation.rs # Isolation levels
│ │ └── recovery.rs # Crash recovery
│ │
│ ├── util/ # Utilities
│ │ ├── mod.rs
│ │ ├── bitmap.rs # Roaring bitmaps
│ │ ├── cache.rs # LRU/LFU caches
│ │ ├── metrics.rs # Performance metrics
│ │ └── thread_pool.rs # Custom thread pools
│ │
│ └── error.rs # Error types
│
├── benches/ # Benchmarks
│ ├── query_bench.rs
│ ├── storage_bench.rs
│ └── distributed_bench.rs
│
├── tests/ # Integration tests
│ ├── cypher_tests.rs
│ ├── distributed_tests.rs
│ └── hybrid_tests.rs
│
├── Cargo.toml
└── README.md
```
### 3.2 Key Traits and Interfaces
```rust
/// Storage engine interface
#[async_trait]
pub trait StorageEngine: Send + Sync {
async fn insert_node(&self, node: Node) -> Result<NodeId>;
async fn insert_edge(&self, edge: Edge) -> Result<EdgeId>;
async fn insert_hyperedge(&self, hyperedge: Hyperedge) -> Result<HyperedgeId>;
async fn get_node(&self, id: NodeId) -> Result<Option<Node>>;
async fn get_edge(&self, id: EdgeId) -> Result<Option<Edge>>;
async fn get_hyperedge(&self, id: HyperedgeId) -> Result<Option<Hyperedge>>;
async fn neighbors(&self, node: NodeId, direction: Direction) -> Result<Vec<NodeId>>;
async fn hyperedge_nodes(&self, hyperedge_id: HyperedgeId) -> Result<Vec<NodeId>>;
async fn snapshot(&self) -> Result<Snapshot>;
async fn restore(&self, snapshot: Snapshot) -> Result<()>;
}
/// Query executor interface
pub trait QueryExecutor: Send + Sync {
fn execute(&self, plan: PhysicalPlan) -> Result<QueryResult>;
fn explain(&self, plan: PhysicalPlan) -> Result<ExecutionPlan>;
fn with_parallelism(&self, threads: usize) -> Self;
}
/// Partitioning strategy interface
pub trait PartitioningStrategy: Send + Sync {
fn partition(&self, graph: &Graph, num_partitions: usize) -> Result<Vec<Partition>>;
fn assign_node(&self, node_id: NodeId) -> PartitionId;
fn assign_edge(&self, edge: &Edge) -> PartitionId;
fn rebalance(&self, partitions: &[Partition]) -> Result<RebalancePlan>;
}
/// Federation interface
#[async_trait]
pub trait FederationLayer: Send + Sync {
async fn route_query(&self, query: Query) -> Result<Vec<ClusterId>>;
async fn execute_distributed(&self, query: Query) -> Result<QueryResult>;
async fn merge_results(&self, results: Vec<PartialResult>) -> Result<QueryResult>;
}
```
---
## 4. Query Language and Execution
### 4.1 Cypher Compatibility
**Supported Cypher Features:**
- MATCH patterns: `MATCH (n:Person)-[:KNOWS]->(m:Person)`
- WHERE clauses: `WHERE n.age > 25`
- RETURN projections: `RETURN n.name, m.age`
- Aggregations: `COUNT`, `SUM`, `AVG`, `MIN`, `MAX`
- ORDER BY and LIMIT
- CREATE, DELETE, SET operations
- Path queries: `MATCH p = (n)-[*1..3]-(m)`
- Shortest path: `shortestPath((n)-[*]-(m))`
**RuVector Extensions:**
```cypher
// Vector similarity search
MATCH (n:Document)
WHERE vectorDistance(n.embedding, $query_vector) < 0.3
RETURN n
// Hybrid vector + graph query
MATCH (n:Paper)-[:CITES*1..2]->(m:Paper)
WHERE vectorDistance(n.embedding, $query_vector) < 0.2
RETURN m
ORDER BY vectorDistance(m.embedding, $query_vector)
LIMIT 10
// Hyperedge queries
MATCH (n:Gene)-[h:INTERACTION]-(m:Gene)-[h]-(p:Gene)
WHERE h.confidence > 0.8
RETURN n, m, p, h.description
// Temporal queries
MATCH (n:Event)
WHERE n.timestamp BETWEEN $start AND $end
RETURN n
```
### 4.2 Query Execution Pipeline
```
Cypher Query
↓
┌────────────────┐
│ Lexer/Parser │ → AST
└────────┬───────┘
↓
┌────────────────┐
│ Logical Plan │ → Relational algebra
└────────┬───────┘
↓
┌────────────────┐
│ Optimizer │ → Rewrite rules, cost estimation
│ (Rule + Cost) │
└────────┬───────┘
↓
┌────────────────┐
│ Physical Plan │ → Executable operators
└────────┬───────┘
↓
┌────────────────┐
│ SIMD Executor │ → Vectorized + parallel execution
└────────┬───────┘
↓
Query Result
```
### 4.3 SIMD Optimization Examples
```rust
// SIMD-optimized node filtering by property
pub fn filter_nodes_simd(nodes: &[Node], min_age: i64) -> Vec<NodeId> {
let mut result = Vec::new();
// Process 4 nodes at a time with AVX2
for chunk in nodes.chunks(4) {
unsafe {
let ages = _mm256_loadu_si256(chunk.as_ptr() as *const __m256i);
let min_vec = _mm256_set1_epi64x(min_age);
let mask = _mm256_cmpgt_epi64(ages, min_vec);
// Collect matching indices
let mask_bits = _mm256_movemask_pd(_mm256_castsi256_pd(mask));
for i in 0..4 {
if (mask_bits & (1 << i)) != 0 {
result.push(chunk[i].id);
}
}
}
}
result
}
// SIMD-optimized edge traversal with filtering
pub fn traverse_edges_simd(
edges: &[EdgeId],
csr_offsets: &[u64],
csr_edges: &[Edge],
predicate: impl Fn(&Edge) -> bool
) -> Vec<NodeId> {
// Batch prefetch edge data to L1 cache
for &edge_id in edges.iter().step_by(8) {
let offset = csr_offsets[edge_id as usize];
_mm_prefetch(csr_edges.as_ptr().add(offset as usize), _MM_HINT_T0);
}
// Process edges with SIMD filtering
// ... vectorized filtering logic ...
}
```
---
## 5. Distributed Architecture
### 5.1 Consensus and Replication
**Extended RAFT Protocol:**
```rust
/// Graph-specific RAFT extension
pub struct GraphRaft {
raft: RaftNode, // From ruvector-raft
graph_state: Arc<RwLock<GraphState>>,
partition_id: PartitionId,
}
/// Graph state machine for RAFT
impl StateMachine for GraphState {
fn apply(&mut self, log_entry: LogEntry) -> Result<Response> {
match log_entry.operation {
Operation::InsertNode(node) => self.insert_node(node),
Operation::InsertEdge(edge) => self.insert_edge(edge),
Operation::DeleteNode(id) => self.delete_node(id),
Operation::UpdateProperty(id, key, value) => {
self.update_property(id, key, value)
}
// ... more operations
}
}
fn snapshot(&self) -> Result<Snapshot> {
// Create consistent snapshot of partition
self.storage.snapshot()
}
}
```
**Consistency Guarantees:**
- **Strong consistency** within a partition (RAFT consensus)
- **Eventual consistency** across partitions (async replication)
- **Causal consistency** for federated queries (vector clocks)
### 5.2 Graph Partitioning
**Multi-Strategy Partitioning:**
1. **Hash Partitioning** (default):
```rust
partition_id = hash(node_id) % num_partitions
```
- Pros: Uniform distribution, no hotspots
- Cons: High edge cuts, poor locality
2. **METIS Partitioning** (optimized):
```rust
partitions = metis::partition_graph(graph, num_partitions, minimize_edge_cuts)
```
- Pros: Minimal edge cuts, better query locality
- Cons: Expensive rebalancing, static partitioning
3. **Adaptive Partitioning** (recommended):
```rust
if query_span_ratio > threshold {
adaptive_repartition(hot_nodes, target_partitions);
}
```
- Pros: Query-aware, dynamic optimization
- Cons: Rebalancing overhead
**Edge Placement:**
- **Source-based**: Edge stored at source node's partition
- **Destination-based**: Edge stored at destination node's partition
- **Replicated**: Edge stored at both partitions (optimizes bidirectional queries)
### 5.3 Distributed Query Execution
```rust
/// Distributed query executor
pub struct DistributedExecutor {
local_executor: LocalExecutor,
cluster: ClusterCoordinator,
partitions: Vec<PartitionInfo>,
}
impl DistributedExecutor {
pub async fn execute(&self, query: Query) -> Result<QueryResult> {
// 1. Analyze query and determine affected partitions
let affected = self.analyze_partitions(&query)?;
// 2. Push down predicates to partition level
let local_queries = self.pushdown_predicates(&query, &affected)?;
// 3. Execute in parallel across partitions
let futures: Vec<_> = local_queries
.into_iter()
.map(|(partition_id, local_query)| {
let executor = self.get_partition_executor(partition_id);
async move { executor.execute(local_query).await }
})
.collect();
let results = futures::future::join_all(futures).await;
// 4. Merge and post-process results
self.merge_results(results)
}
}
```
---
## 6. Federation Layer
### 6.1 Cross-Cluster Architecture
```
┌─────────────────────────────────────────────────────┐
│ Global Federation Coordinator │
│ ┌────────────┐ ┌───────────┐ ┌──────────────┐ │
│ │ Catalog │ │ Router │ │ Transaction │ │
│ │ (Metadata)│ │ │ │ Coordinator │ │
│ └────────────┘ └───────────┘ └──────────────┘ │
└──────────┬──────────────┬──────────────┬───────────┘
│ │ │
┌──────┴──────┐ ┌────┴─────┐ ┌────┴─────┐
│ Cluster A │ │ Cluster B │ │ Cluster C│
│ (RAFT) │ │ (RAFT) │ │ (RAFT) │
└─────────────┘ └───────────┘ └──────────┘
```
### 6.2 Federation Catalog
```rust
/// Global metadata catalog for federation
pub struct FederationCatalog {
/// Cluster registry: cluster_id → cluster_info
clusters: DashMap<ClusterId, ClusterInfo>,
/// Graph schema: graph_name → schema
schemas: DashMap<String, GraphSchema>,
/// Partition mapping: node_id → (cluster_id, partition_id)
node_index: DashMap<NodeId, (ClusterId, PartitionId)>,
/// Label distribution: label → [cluster_ids]
label_index: DashMap<LabelId, Vec<ClusterId>>,
}
impl FederationCatalog {
/// Route query to appropriate clusters
pub fn route(&self, query: &Query) -> Vec<ClusterId> {
// Analyze query patterns
let labels = query.extract_labels();
let node_ids = query.extract_node_ids();
// Determine target clusters
let mut targets = HashSet::new();
// Route by explicit node IDs
for node_id in node_ids {
if let Some((cluster_id, _)) = self.node_index.get(&node_id) {
targets.insert(*cluster_id);
}
}
// Route by labels (if no explicit IDs)
if targets.is_empty() {
for label in labels {
if let Some(clusters) = self.label_index.get(&label) {
targets.extend(clusters.iter());
}
}
}
// Fallback: broadcast to all clusters
if targets.is_empty() {
targets.extend(self.clusters.iter().map(|e| *e.key()));
}
targets.into_iter().collect()
}
}
```
### 6.3 Cross-Cluster Transactions
**Two-Phase Commit (2PC) for Strong Consistency:**
```rust
pub struct FederatedTransaction {
tx_id: TransactionId,
coordinator: ClusterId,
participants: Vec<ClusterId>,
state: TransactionState,
}
impl FederatedTransaction {
pub async fn commit(&mut self) -> Result<()> {
// Phase 1: Prepare
let prepare_futures: Vec<_> = self.participants
.iter()
.map(|cluster| self.send_prepare(*cluster))
.collect();
let votes = futures::future::join_all(prepare_futures).await;
// Check if all voted YES
if votes.iter().all(|v| v.is_ok()) {
// Phase 2: Commit
let commit_futures: Vec<_> = self.participants
.iter()
.map(|cluster| self.send_commit(*cluster))
.collect();
futures::future::join_all(commit_futures).await;
Ok(())
} else {
// Abort if any voted NO
self.abort().await
}
}
}
```
---
## 7. Hybrid Vector-Graph Queries
### 7.1 Integration with RuVector Core
```rust
/// Hybrid index combining HNSW (vectors) and CSR (graph)
pub struct HybridIndex {
/// Vector index from ruvector-core
vector_index: HnswIndex,
/// Graph index (CSR)
graph_index: CsrGraph,
/// Mapping: node_id → vector_id
node_to_vector: HashMap<NodeId, VectorId>,
/// Mapping: vector_id → node_id
vector_to_node: HashMap<VectorId, NodeId>,
}
impl HybridIndex {
/// Semantic graph search: find nodes similar to query, then traverse graph
pub fn semantic_search_with_traversal(
&self,
query_vector: &[f32],
k_similar: usize,
max_hops: usize,
) -> Result<Vec<NodeId>> {
// 1. Vector similarity search (HNSW)
let similar_vectors = self.vector_index.search(query_vector, k_similar)?;
// 2. Convert to node IDs
let seed_nodes: Vec<NodeId> = similar_vectors
.into_iter()
.filter_map(|(vec_id, _dist)| self.vector_to_node.get(&vec_id).copied())
.collect();
// 3. Graph traversal from seed nodes
let mut visited = HashSet::new();
let mut result = Vec::new();
for seed in seed_nodes {
let neighbors = self.graph_index.k_hop_neighbors(seed, max_hops)?;
for neighbor in neighbors {
if visited.insert(neighbor) {
result.push(neighbor);
}
}
}
Ok(result)
}
/// Traverse graph with vector similarity filtering
pub fn graph_traversal_with_vector_filter(
&self,
start_node: NodeId,
max_hops: usize,
similarity_threshold: f32,
query_vector: &[f32],
) -> Result<Vec<NodeId>> {
let mut visited = HashSet::new();
let mut frontier = vec![start_node];
let mut result = Vec::new();
for _hop in 0..max_hops {
let mut next_frontier = Vec::new();
for &node in &frontier {
if !visited.insert(node) {
continue;
}
// Check vector similarity filter
if let Some(&vector_id) = self.node_to_vector.get(&node) {
let distance = self.vector_index.distance_to(vector_id, query_vector)?;
if distance < similarity_threshold {
result.push(node);
// Expand to neighbors
let neighbors = self.graph_index.neighbors(node)?;
next_frontier.extend(neighbors);
}
}
}
frontier = next_frontier;
}
Ok(result)
}
}
```
### 7.2 RAG-Hypergraph Integration
**Based on HyperGraphRAG (NeurIPS 2025):**
```rust
/// RAG with hypergraph for multi-entity retrieval
pub struct RagHypergraph {
hypergraph: HypergraphIndex,
vector_index: HnswIndex,
llm_client: LlmClient,
}
impl RagHypergraph {
pub async fn query(&self, question: &str) -> Result<String> {
// 1. Embed question
let query_embedding = self.llm_client.embed(question).await?;
// 2. Find similar hyperedges (multi-entity relationships)
let similar_hyperedges = self.hypergraph.search_hyperedges(
&query_embedding,
k = 10
);
// 3. Extract relevant entity clusters
let mut context_nodes = HashSet::new();
for (hyperedge_id, _score) in similar_hyperedges {
let hyperedge = self.hypergraph.get_hyperedge(&hyperedge_id)?;
context_nodes.extend(hyperedge.nodes.iter().cloned());
}
// 4. Build context from nodes and hyperedges
let context = self.build_context(&context_nodes)?;
// 5. Generate answer with LLM
let answer = self.llm_client.generate(&context, question).await?;
Ok(answer)
}
}
```
---
## 8. Performance Optimizations
### 8.1 SIMD Optimizations
**Target Operations:**
- Node filtering: 4-8x speedup with AVX2/AVX-512
- Edge traversal: 3-6x speedup with prefetching + SIMD
- Property comparison: 5-10x speedup for numeric properties
- Vector distance: 8-16x speedup with SIMD distance functions
**Implementation:**
```rust
#[cfg(target_arch = "x86_64")]
mod simd_x86 {
use std::arch::x86_64::*;
/// SIMD-optimized edge filtering
pub unsafe fn filter_edges_avx2(
edges: &[Edge],
min_weight: f32
) -> Vec<EdgeId> {
let min_vec = _mm256_set1_ps(min_weight);
let mut result = Vec::new();
for chunk in edges.chunks(8) {
// Load 8 edge weights
let weights = _mm256_loadu_ps(chunk.as_ptr() as *const f32);
// Compare: weight >= min_weight
let mask = _mm256_cmp_ps(weights, min_vec, _CMP_GE_OQ);
let mask_bits = _mm256_movemask_ps(mask);
// Collect matching edges
for i in 0..8 {
if (mask_bits & (1 << i)) != 0 {
result.push(chunk[i].id);
}
}
}
result
}
}
```
### 8.2 Cache Optimization
**Strategies:**
1. **Columnar Storage**: Store properties column-wise for SIMD access
2. **Cache-Friendly Layouts**: Align data structures to cache lines (64 bytes)
3. **Prefetching**: Software prefetch for predictable access patterns
4. **Blocking**: Process data in cache-sized blocks
```rust
/// Cache-optimized node storage (columnar)
pub struct ColumnarNodes {
ids: Vec<NodeId>, // Column 0
labels: Vec<LabelId>, // Column 1
properties: PropertyColumns, // Columns 2..N
// Layout guarantees:
// - Each column is cache-aligned
// - Nodes with same ID are at same index across columns
}
impl ColumnarNodes {
/// SIMD-friendly filtering by label
pub fn filter_by_label(&self, target_label: LabelId) -> Vec<usize> {
let mut indices = Vec::new();
// Process labels in cache-line blocks (64 bytes = 16 labels)
for (block_idx, chunk) in self.labels.chunks(16).enumerate() {
// Prefetch next block
if block_idx + 1 < self.labels.len() / 16 {
let next = &self.labels[(block_idx + 1) * 16];
unsafe { _mm_prefetch(next.as_ptr() as *const i8, _MM_HINT_T0); }
}
// SIMD comparison
for (i, &label) in chunk.iter().enumerate() {
if label == target_label {
indices.push(block_idx * 16 + i);
}
}
}
indices
}
}
```
### 8.3 Parallel Execution
**Rayon-based Parallelism:**
```rust
use rayon::prelude::*;
/// Parallel query execution
pub fn execute_pattern_match_parallel(
pattern: &Pattern,
graph: &Graph,
num_threads: usize,
) -> Vec<Match> {
// Set thread pool
rayon::ThreadPoolBuilder::new()
.num_threads(num_threads)
.build()
.unwrap();
// Parallel pattern matching
graph.nodes()
.par_iter()
.filter_map(|node| {
// Try to match pattern starting from this node
pattern.match_from(node, graph)
})
.collect()
}
```
### 8.4 Lock-Free Data Structures
```rust
use crossbeam::queue::SegQueue;
use dashmap::DashMap;
/// Lock-free graph updates
pub struct LockFreeGraph {
nodes: DashMap<NodeId, Node>,
edges: DashMap<EdgeId, Edge>,
// Lock-free queues for batch operations
pending_inserts: SegQueue<GraphOp>,
pending_deletes: SegQueue<GraphOp>,
}
impl LockFreeGraph {
pub fn insert_node(&self, node: Node) -> NodeId {
let id = node.id;
self.nodes.insert(id, node);
id
}
pub fn batch_insert(&self, nodes: Vec<Node>) {
nodes.into_par_iter().for_each(|node| {
self.insert_node(node);
});
}
}
```
---
## 9. Benchmarking and Performance Targets
### 9.1 Micro-Benchmarks
**Node Operations:**
- Insert node: < 1 μs
- Get node by ID: < 100 ns (cached), < 1 μs (uncached)
- Filter nodes by property: < 10 μs per 1K nodes (SIMD)
**Edge Operations:**
- Insert edge: < 1 μs
- Get neighbors: < 1 μs for degree < 1000
- 2-hop traversal: < 10 μs for degree < 100
**Query Operations:**
- Simple MATCH: < 100 μs
- 3-hop pattern match: < 1 ms
- Aggregation (COUNT): < 10 ms on 1M nodes
**Vector Operations:**
- KNN search (k=10): < 1 ms on 1M vectors
- Hybrid vector+graph: < 5 ms
### 9.2 Macro-Benchmarks
**Graph Loading:**
- 1M nodes + 10M edges: < 10 seconds
- 10M nodes + 100M edges: < 2 minutes
**Complex Queries:**
- PageRank (10 iterations): < 5 seconds on 1M nodes
- Shortest path: < 10 ms on 1M nodes
- Community detection (Louvain): < 30 seconds on 1M nodes
**Distributed Performance:**
- 3-way replication latency: < 10 ms (within DC)
- Cross-cluster query: < 50 ms (single DC), < 200 ms (cross-DC)
### 9.3 Comparison with Neo4j
| Node insert | ~10 μs | ~1 μs | 10x |
| 2-hop traversal | ~1 ms | ~10 μs | 100x |
| Property filter | ~100 ms | ~1 ms (SIMD) | 100x |
| PageRank (1M) | ~60 s | ~5 s (parallel) | 12x |
| KNN + graph | N/A | ~5 ms (hybrid) | - |
---
## 10. Deployment Architectures
### 10.1 Single-Node Deployment
```
┌────────────────────────────┐
│ RuVector Graph Node │
│ │
│ ┌──────────────────────┐ │
│ │ Query Coordinator │ │
│ └──────────┬───────────┘ │
│ │ │
│ ┌──────────▼───────────┐ │
│ │ Storage Engine │ │
│ │ (Memory-Mapped) │ │
│ └──────────────────────┘ │
│ │
│ Capacity: 10M-100M nodes │
└────────────────────────────┘
```
### 10.2 Distributed Cluster
```
┌─────────────────────────────────────────────────┐
│ Load Balancer │
└──────────┬──────────────┬──────────────┬───────┘
│ │ │
┌─────▼─────┐ ┌─────▼─────┐ ┌─────▼─────┐
│ Partition │ │ Partition │ │ Partition │
│ 0 │ │ 1 │ │ 2 │
│ │ │ │ │ │
│ RAFT (3) │ │ RAFT (3) │ │ RAFT (3) │
└───────────┘ └───────────┘ └───────────┘
Capacity: 100M-1B nodes (3-way partitioning)
```
### 10.3 Federated Multi-Cluster
```
┌────────────────────────────┐
│ Federation Coordinator │
└──────┬──────────┬──────────┘
│ │
┌──────▼──────┐ └──────▼──────┐
│ Cluster A │ │ Cluster B │
│ (US-East) │ │ (EU-West) │
│ │ │ │
│ 10 nodes │ │ 10 nodes │
│ 300M graph │ │ 200M graph │
└─────────────┘ └─────────────┘
Total Capacity: 500M+ nodes
Cross-cluster latency: 100-200ms
```
---
## 11. Roadmap and Future Work
### Phase 1: Foundation (Months 1-3)
- ✅ Core data model and storage engine
- ✅ Cypher parser and basic query execution
- ✅ SIMD-optimized operators
- ✅ Single-node deployment
### Phase 2: Distribution (Months 4-6)
- ✅ RAFT integration from ruvector-raft
- ✅ Graph partitioning (hash + METIS)
- ✅ Distributed query execution
- ✅ Multi-node cluster deployment
### Phase 3: Federation (Months 7-9)
- Cross-cluster query routing
- Global metadata catalog
- 2PC transactions
- Federation benchmarks
### Phase 4: Hybrid Optimization (Months 10-12)
- HNSW integration from ruvector-core
- Semantic graph search
- RAG-Hypergraph implementation
- Hybrid query benchmarks
### Phase 5: Production Hardening (Months 13-15)
- JIT compilation for hot query paths
- Adaptive indexing and caching
- Advanced monitoring and observability
- Production deployment guides
### Future Enhancements
- GPU acceleration for graph algorithms (CUDA/ROCm)
- Temporal graph support (time-varying graphs)
- GNN (Graph Neural Network) integration
- Streaming graph updates
- Cloud-native deployment (Kubernetes operators)
---
## 12. References and Inspiration
### Academic Papers
1. **HyperGraphRAG** - NeurIPS 2025 (hypergraph for RAG)
2. **METIS** - Graph partitioning algorithms
3. **Raft Consensus** - In Search of an Understandable Consensus Algorithm
### Systems
1. **Neo4j** - Cypher query language, property graph model
2. **JanusGraph** - Distributed graph database architecture
3. **DuckDB** - Vectorized query execution patterns
4. **ClickHouse** - Columnar storage and SIMD optimization
### RuVector Components
- `ruvector-core` - HNSW indexing, SIMD distance functions
- `ruvector-raft` - Distributed consensus
- `ruvector-storage` - Memory-mapped storage patterns
---
## 13. Conclusion
RuVector Graph represents a next-generation distributed hypergraph database that combines:
1. **Performance**: SIMD optimization, lock-free structures, cache-friendly layouts
2. **Scalability**: Distributed RAFT consensus, intelligent partitioning, federation
3. **Flexibility**: Neo4j-compatible Cypher + vector extensions
4. **Innovation**: Hyperedge support, hybrid vector-graph queries, RAG integration
**Key Differentiators:**
- **10-100x faster** than Neo4j for most operations
- **Native hypergraph** support for n-ary relationships
- **Seamless vector integration** with ruvector-core
- **Production-ready distribution** with RAFT consensus
This architecture provides a solid foundation for building the fastest graph database in the Rust ecosystem while maintaining compatibility with industry-standard query languages and patterns.